import React, { useState } from 'react'
import Count from './Count'
export default function App() {
  const [a, setA] = useState(0)
  return (
    <div>
      <button
        onClick={() => {
          setA(1)
        }}
      >
        按钮
      </button>
      {a === 0 && <Count></Count>}
    </div>
  )
}
